JPH0136091B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a copying apparatus that projects a negative or positive image onto a charged photoreceptor to obtain a positive copy image.

Conventionally, microfilm printers that use microfilm originals and copiers that use reflective originals such as documents have been available as standalone products, but when using both types of originals, two products are required, which is expensive. It was inconvenient.

In view of this, an apparatus combining a microfilm printer and an electrophotographic copying machine has been proposed. When copying a reflective original with a positive image, such a device projects the reflected light from the original onto a photoreceptor and develops the electrostatic latent image formed on the photoreceptor using a regular developing method to create a copy. When copying a microfilm original with a negative image, the light transmitted through the microfilm is projected onto a photoreceptor, and the electrostatic latent image formed on the photoreceptor is developed using a so-called reversal development method to make a copy. There is.

In a normal developing method, for example, an electrophotographic photoreceptor is charged to a polarity different from that of a developing toner, and development is performed by applying the toner to an electrostatic latent image on the photoreceptor. On the other hand, in the reversal development method, a photoreceptor is charged to the same polarity as the developing toner, and development is performed by applying the toner to the photoreceptor.

In the above-mentioned type of device, if the photoconductor is larger than the projection original, the cover for the reflective original is not used during exposure, or even if a cover is used, the reflective original such as a book may be copied. Since there is an area on the photoreceptor corresponding to the surrounding area (the periphery of the photoreceptor) where no light is projected, a black frame is formed at the periphery of the photoreceptor. Also, when copying microfilm, the peripheral edge of the negative image on the microfilm is generally transparent, so during exposure, the part of the photoreceptor (periphery of the photoreceptor) corresponding to the transparent peripheral area of the microfilm image is exposed to light. Since there is an area where is projected, a black frame is formed around the periphery of the photoreceptor. Therefore, no matter which original is used, a black frame is formed around the periphery of the photoreceptor, which is very unsightly and has the problem of lowering the commercial value of the copy.

Therefore, in Japanese Patent Application Laid-open No. 47-4483, a mask with an aperture of a certain size is placed in the image projection optical path, and when copying a negative image, the mask blocks the optical path around the edge of the negative image, and the positive image is When copying a positive image, a photoreceptor corresponding to the periphery of the positive image is exposed to prevent a black frame from forming at the periphery of the copied image, but it is not possible to obtain a copy of any area of a negative or positive image. There was a problem that I couldn't solve.

The present invention provides a copying apparatus that solves the above problems. The present invention will be explained below with reference to the drawings.

The drawing shows an electrophotographic copying apparatus according to an embodiment of the present invention. Reference numeral 1 designates a microfilm projection section, and a reflective mirror 3, a lamp 4, a microfilm 5 having a negative image, and a first projection lens 6 are disposed inside the dark box 2, and a Fresnel lens is provided in the lower opening of the dark box 2. 7 are arranged.

The dark box 2 is rotatable about the axis 8 between the wiring position 2' and the solid line position, and is placed at the solid line position when copying a microfilm image. When the dark box 2 is placed at the copying position 9, the Fresnel lens 7 is placed in close contact with the transparent plate 10.

As shown in FIG. 2, the microfilm 5 is transparent around the frame f having a negative image.
Diagonal lines indicate opaque areas.

The image on the microfilm 5 is transferred to the first projection lens 6
The image formed on the Fresnel lens 7 is projected onto the exposure position 12 where the photosensitive paper S is placed by the second projection lens 11.
is imaged. 15 indicates a copying section, and paper feed mechanism 1
The photosensitive paper (electrofax paper) S sent to the copying section 15 by the charging section 17 is uniformly charged to a predetermined polarity by the charging section 17, and then carried to the exposure position 12 by the belt 18, where it is transferred to the exposure position 12 by the belt 18. Stop. At this time, when the dark box 2 is placed at the copying position 9, the lamp 4 is turned on, and the transmitted light from the microfilm 5 passes through the projection lenses 6 and 11 and reaches the exposure position 12.
The image on the microfilm is formed on photosensitive paper S. After the exposure, the photosensitive paper is conveyed again by the belt 18 to the developing section 19, where it is immersed in a developer to visualize the electrostatic latent image. Next, the photosensitive paper is heated and fixed as it passes through the fixing section 20, and then transferred to the output tray 21.
is discharged.

Raw originals such as general documents and drawings, that is, reflective originals with positive images, are placed on the transparent plate 8. At this time, the dark box 2 is placed at the broken line position 2'.

The reflective original placed at the copying position 9 is illuminated by the lamp 25, and the light beam reflected from the reflective original passes through the second projection lens 11 and reaches the exposure position 12, where the image of the reflective original is formed on the photosensitive paper S. Ru. Note that when the photosensitive paper S is sent to the copying section 15, the charging polarity of the charging section 17 is switched depending on the type of original to be copied. That is, the charger 17 charges the photosensitive paper to a polarity different from the polarity of the developing toner in the developing section 19 when copying a reflective original, that is, a positive image, and charges the photosensitive paper to a polarity different from that of the developing toner in the developing section 19 when copying a microfilm original, that is, a negative image. Charge the photosensitive paper to the same polarity as the toner. Note that when using a microfilm with a positive image, it is charged in the same way as a reflective original.

Reference numeral 30 denotes a light-shielding plate that can be moved in and out of the projection optical path in order to shield any part of the photosensitive paper. Each light-shielding plate 30 is connected to an operating knob 32 outside the machine via a connecting mechanism 31, and the operating knob is operated. This allows their position to be adjusted so that any area of the photosensitive paper can be masked. Note that the light shielding plates 30 are arranged on each of the four sides of the exposure position 12. The light shielding plate 30 is placed close to the surface of the belt 18, and is moved parallel to the surface of the belt 18 by operating a knob 32. It is inserted into the projection optical path and positioned to block the optical path around the projected image. Note that a light shielding plate may be placed near the copying position 9.

A light emitting body 35 in which a light emitting element made of electroluminescence is laminated between a pair of transparent electrodes is disposed on the side of the light shielding plate 30 facing the belt 18 . It emits light when operated. That is, when the operation switch 36 is turned on, a voltage is applied between the pair of transparent electrodes and the light emitting element emits light, and when it is turned off, no voltage is applied and no light is emitted. This operation switch 36 is operated depending on the type of original to be copied, and is turned on when copying a reflective original with a positive image, and turned off when copying a microfilm original with a negative image. . Note that when a microfilm with a negative image has an opaque peripheral area, or when a microfilm with a positive image is used and the peripheral area of the microfilm image is transparent, a light shielding plate is placed outside the optical path.

Therefore, when the light-shielding plate 30 is inserted into the optical path, the switch 36 is turned on when copying a reflective original, and the light emitting body emits light, thereby exposing the photosensitive material corresponding to the light path blocked by the light-shielding plate 30. Portion l of the paper is exposed to the light of the phosphor, and this exposed location of the photoreceptor is not developed. On the other hand, when copying a microfilm original, the switch 36 is turned off, so that the light emitter does not emit light, and the portion l of the photosensitive paper corresponding to the optical path closed by the light shielding plate 30 is not exposed to light. This unexposed part of the body is not developed. Note that when using a microfilm with a positive image and the periphery of the positive image is opaque, the knob 32 and the switch 36 are operated respectively in the same manner as for a reflective original.

As described above, toner does not adhere to the periphery of the copied image when using either a reflective original or a microfilm original, thereby preventing excess toner consumption and obtaining high-quality copies. I can do it.

Although a light emitting element is used in the above embodiment,
The light shielding plate may have a reflective surface on the belt surface side, and the light from the lamp may be projected onto this reflective surface, and the reflected light from this reflective surface may be projected onto the photoreceptor. Of course, this lamp blinks depending on the type of document. The present invention can also be applied to a slit electrophotographic transfer type copying machine, and other known copying systems capable of normal development and reversal development can be applied.

The present invention can also be used to prevent unnecessary information such as search marks and frame numbers on microfilm from being recorded on copies, and it is possible to easily create copies from which such information has been deleted, regardless of whether the image is negative or positive. can be obtained.

As described above, according to the present invention, it is possible to erase an image in any area on the surface of a photoreceptor, regardless of whether it is a negative image or a positive image, and moreover, it is possible to erase an image in any area on the surface of a photoreceptor, and moreover, it is possible to erase an image in any area on the surface of a photoreceptor, and moreover, it is possible to erase an image in any area on the surface of a photoreceptor, and moreover, it is possible to erase an image in any area on the surface of a photoreceptor, and moreover, it is possible to erase an image in any area on the surface of a photoreceptor, and moreover, it is possible to erase an image on an arbitrary area on the surface of a photoreceptor, and moreover, it is possible to erase an image in any area on the surface of a photoreceptor, and moreover, it is possible to erase an image on an arbitrary area on the surface of a photoreceptor. Since they move integrally, there is no need to provide a device to move them independently, and the structure of the device can be simplified.

Furthermore, since the image erasing area can be adjusted by a common setting means, erasing work can be easily performed.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of an electrophotographic copying apparatus showing one embodiment of the present invention, and FIG. 2 is a front view of a microfilm. 1... Microfilm projection unit, 5... Microfilm, 30... Light shielding plate, 35... Light emitter,
S...Photosensitive paper.

Claims (1)

[Claims] 1. An optical means for projecting a negative image or a positive image onto a charged photoreceptor, a light blocking member that is movable within and outside the image projection optical path, and is capable of adjusting the optical path blocking position, and a light blocking member. An irradiation means that is integrally movable and is provided on the opposite side of the light blocking surface of the light blocking member and irradiates the surface of the photoreceptor corresponding to the light path blocking position in a timely manner; means for setting an area where the image of the body surface is to be erased; input means for inputting the type of image to be copied; and input when the light path corresponding to the area of the image to be erased is blocked by moving the light blocking member. 1. A copying apparatus comprising: means for controlling the operation of the irradiation means based on input from the means.